Leaks in the bathroom sink area

I have a 2009 Cameo 35SB3 with some intermittent fresh water leaks in the bathroom dripping into the garage area. I discovered that the sink has some small cracks from the previous owner overtightening the drain tailpiece nut. I can fix that temporarily with a bit if silicone until I find a new sink that fits. (any recommendations? dimensions are 14 x 17 oval)
I also discovered a leak in the water supply pipe under the corner of the sink. There is a …device… like an elbow or vent stack for the drain but it is in the freshwater pressure line. (picture attached) anyone know what this is for? IS it a pressure compensator to reduce water hammer? or can I remove it when I repair the leak?

The device in your picture is a check valve vacuum breaker for the black tank flush. It prevents water from being siphoned from the black tank when you rinse it. The only time this would leak is when you are flushing your black tank.

Here is a link to one on Amazon.

Chip

If the vacuum breaker is defective you really need to replace it and not bypass it.
Chip

The sink in our 2011 is stainless-steel. This is a replacement that would work on ours. You might want to see if this would work to replace yours.

http://www.dyersonline.com/lasalle-bris … -sink.html

Thanks Chip, That makes sense since both times it appeared was after I rinsed the tank. I will look for a replacement.
Thanks Jim and Jane for the link. My sink is the 14 x 17 Oval with 3 holes, in bone or off-white. I see that Dyers only has white or silver metallic. I would like the bone color or a chocolate brown to match the shower.

Here is a much better substitution for the plastic check valve and it is much cheaper. You can probably pick one up at Home Depot or Lowes. You will need to purchase two nipples to install it.

Chip

Here is another site to look for the sink.
Chip
http://www.pellandent.com/RV_Products_L … egoryID=87